Exploratory Costs (Tables)

3 Months Ended

Mar. 31, 2018

Capitalized exploratory well and project activity

The following table reflects the Company's capitalized exploratory well and project activity during the three months ended March 31, 2018:



	Three Months Ended March 31, 2018
	(in millions)
Beginning capitalized exploratory well costs	$	505
Additions to exploratory well costs pending the determination of proved reserves	582
Reclassification due to determination of proved reserves	(607		)
Exploratory well costs charged to exploration and abandonment expense	(4		)
Ending capitalized exploratory well costs	$	476

Capitalized exploratory costs and the number of projects for which exploratory costs have been capitalized

The following table provides an aging as of March 31, 2018 and December 31, 2017 of capitalized exploratory costs and the number of projects for which exploratory well costs have been capitalized for a period greater than one year, based on the date drilling was completed:



	March 31, 2018		December 31, 2017
	(in millions, except well counts)
Capitalized exploratory well costs that have been suspended:
One year or less	$	464	$	493
More than one year	12		12
	$	476	$	505
Number of wells or projects with exploratory well costs that have been suspended for a period greater than one year	7		7